Unloading valve



June 21 1927.

J. ILE VALLEY UNLOADING VALVE Filed Nov. 24, 1926 W @.M R 5 K A P L u v\\\\\ ///.y/` /M/ K B filma v H125' ATTo EY Patented June 21, 1927.y

UNITED STATES 1,632,841 PATENT OFFICE.

JOHN LE VALLEY, OIF PAINTED POST, NEW YORK, ASSIGNOR TO INGERSOLL-RAND COMPANY, OF JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

UNLOADING VALVE.

Application iled November 24, 1926. Serial No. 150,473.

more particularly t0 an unloading valve for compressors of the multi-cylinder type.

The objects of the invention are to; unload the cylinders whenever the receiver pressure reaches a certain predetermined value andfto produce a compact and simplified unloading mechanism which requires only a few simple parts and which may be easily operated and cheaply maintained. These objects are accomplished in the present instance by a reciprocablervalve disposed in the Wall between the cylinder chambers to control the passage through which communication between the cylinder chambers may be established.

Other objects will be in partobvious and in part pointed out hereinafter.

The invention consists of the combination of elements and features of construction subtantially as hereinafter described andmore particularly pointed out in the appended claims and illustrated in the accompanying drawing, in which is illustrated a sectional elevation of so much of a compressor as will serve to illustrate the invention. Referring more particularly to the drawing, A .designates a cylinder having in this instancev a pair of cylinder chambers B. Pistons C reciprocable lin the cylinder chambers B are provided withgconnecting rods D which may be operatively connected to a suitable prime mover (lnot shown). I

Supported by the cy inder A is a head E having a' chamber F .which communicates with a receiver tank Gthrough a conduit H. The head E may be secured to the cylinder A in any suitable manner. In the present i instance bolts J are indicated for that purose. r p In an inner wall K of the valve-box E are seated discharge valves L of a well known type for controlling the exhaust of pressure fluid from the cylinder chambers B into the chamber F.

- In accordance with the resent invention,- a passage O is formed liirough a wall P between the c linder chambers B, preferably near the ischar'ge end of thecylinder chambers and in this instance is intersected by a longitudinal bore Q in the wall P.

Disposed in the bore Q is ai-valve R having end heads S- and T which codperate slidably with the bore Q. The heads S and T are connected by a stem U and the head S cari. This invention relates to compressors, but ries at its upper end ali-lange V which extends into a recess W of the valve box E. In the construction shown the flange 'V is adapted to seat on the bottom of the recess W for limiting downward or inward movement of the valveR in the bore Q.

To the end that the valve S may be suitably `held in its closed position during the normal operation of the compressor, aspring Z is disposed 1n the recess W to seat with one end on the flange V of the valve R and with its other end against a cover' b screwed in the end of the recess Wto form a closure therefor.

Any suitable means may be provided for controlling the admission of pressure fluid from the receiver tank G to the lend of the bore Q. Such means consist in the present instance, of a pipe c. which communicates with the bore Q through a port d. The pipe c is provided with a pressure controlling valve e preferably of the type described in United States Patent No. 1,138,278 granted May 4, 1915, to J. H. Castle and W. Gf Rogers. Reference `may be had to this patent for a detail description of the controlling valve. However, it is to be understood that the invention is not dependent upon its successful functioning on this particular vtype of valve, but that any suitable device will be held closed Vby the spring Z. Howf ever, after the pressure in the` receiver tank kGr rises to or exceeds the predetermined pressure the valve e will function in a well uns` derstood manner to admit pressure fluid from the receiver tank G into the bore Q. Such pressure fluid acting against the lower or inner end of the valve .R will overcome the pressure exerted by the sprmg -Z. and will raise the valve R until .the valve head S uncoversv the passage O. In this way the cylinder chambers B will be short-circuited y casing, 'thus eliminating anyv objectionabley so that any airexisting in the cylinder chambers B will be discharged through the passage O andaround the valve stem U from one chamber B to the other chamber'." The pistons C will then reciprocate in the chamers B without doing any .actual work of tion between the cylinder' chambers B.

The Apresent invention has been found to be particularly desirable in compressors of the portable type for the reason that it may be applied to a. multi-cylinder compressor Without materially increasing the weight thereof. The device is compact and of simple construction. 1t mayfbe readily installed in the compressor and is capable of rendering service for a long period of time without requiring frequent inspection and adjust-V Another desirable feature of the` ment. present invention is that the unloading valve is completelyl housed within the compressor piojections which may become disarranged orsbroken due to the rough usage which machines of this type frequently receive.

I claim: v l.' In a compressor having a plurality of cylinder chambers, a common Wall between tie chambers having a passage to establish communication between the chambers, said wall having a longitudinal bore intersectln the passage, and a valve in the bore expose at one end to storage pressure whereby it is actuated for establishing communication between the chambers whenever the storage pressure reaches a certain predetermined value.

2.1m a compressor having a plurality of cylinder chambers, a common wall between the chambers having a passage for establishing' communication between the chambers, said wall also having alongitudinal bore intersecting the passage, a valve reciprocable in the bore to control the passage, means for admitting pressure fluid from a receiver to the bore for opening the valve whenever the pressure in such receiver rises to a cer- V tain predeterminedvalue, and a spring normally holding said' valve closed. o

In testimony whereof I have signed this specification. i

JOHN LE VALLEY. 

